Questions tagged [snubber]

A snubber is a circuit used to suppress transient voltages in electrical circuits. It can include RC snubbers that comprise a resistor and a capacitor in series, often used for AC circuits, and also a diode used across relays and other inductive components to suppress their inductive 'kickback'.

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Inverter MOSFET Snubber: RC or Schottky diode?

I've researched this question and found a lot of theory, but not much practical anecdotal experience. I would like to hear from those with physical knowledge of this. I've constructed a transformer ...
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RLD + RC Snubber for MOSFET

I'm currently making a DC-DC SMPS power supply that converts 331VDC (rectified from 240VAC) to 60VDC with a maximum output current of 10 amps. I've asked once on this forum about a general problem on ...
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Snubber circuit for electromagnet

I have run into the same problem described here and here, when I added diode to electromagnet. Basically, the magnet still holds with about 20kg force several minutes after removing power. The ...
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What causes spikes on a primary push-pull transformer with good snubber and tvs?

I am repairing 8 second-hand microgrid inverters from 2013. The internal structure is a push-pull sinusoidal current generator. DC input 12 to 28V, 250W. The primary side suffers from a design problem....
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Noise suppression circuits for a 120VAC motor

I am building a circuit for a relay that controls power to a 1000 watt pump motor. I want to do what I can to reduce noise and failure of the circuits from transients etc. Here is my schematic: I ...
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Decoding SPICE Model for onsemi SZ1SMB5939BT3G 30V Zener

I would like to model using the onsemi 1SMB5936BT3G (30V Zener Diode) SPICE model, but the SPICE model is not acting as I am expecting. Built-in LTspice Zeners clamp the kickback no problem but the ...
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Distorted output waveform and snubber heating in 3level 3 phase inverter

We are working on 3-level 3-phase 400Hz inverter (110Vrms). The problem is that the output wave still have some harmonics of the switching frequency. The snubbers are heating up rapidly when connected ...
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AC element control using TRIAC and optocoupler

I recently came across this circuit and I'm trying to understand it. This is designed to control an AC heater using a T435-600B-TR TRIAC and an MOC3063S optocoupler, connected to an Arduino Uno. From ...
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Arc suppression on electromagnet circuit

I have an application where an aluminum arm is contacting a steel spring and there is a lot of arcing. The contact energizes a 12v electromagnet with a 47ohm coil drawing 250mA and a 4700uF cap to ...
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Can I use a single snubber circuit for multiple triacs?

I am building a triac sprinkler controller using BT136S-800,118 triacs with a microcontroller for control. The triac driver (MOC3021M) suggests a snubber circuit for an inductive load. I have two ...
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Snubber Filter Circuit Not Working Triac Dimmer

Hi I am working on a project using a triac to do phase control dimming of 120V ac powered devices. I recently translated my project from perfboard to SMT using an SMT fabrication service. The project ...
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Trace clearance and creepage distance between similar high AC voltage paths

In my project I need to control 2 relays from ESP-12E, I have isolated AC & DC side in my PCB design by 4mm PCB Material : FR4, with general Silkscreen coating (green polymer coated) According to ...
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Unwanted motor influence (RC snubber?)

Trying to make motors control, but have very significant influence of the motors between each other. When first motor is stopped (by built in limiter) second one (stopped) start turning cca 1/4 of ...
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Understanding flyback power supply with weird snubber circuit, and general function?

Hello fellow wanderers of the electromagnetic plains, I'm looking to replicate the function of the below pictured reference design, just a simple 230VAC SMPS using an iW1700 chip (72kHz operation), ...
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Transformer energy snubber

I own an older PC speaker set with a 10 V AC power supply. The power-cube transformer not only has a sine with flatted tops, but also, when I turn off the speaker set, my sleeping PC wakes up. I guess ...
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Triac driving motor with limit switch, needs protection?

I'm trying to drive a bunch of motorized ball valves from an ESP32. These valves have a 230V AC motor with one common wire, and two wires to set direction (open/close). When powered between common and ...
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TRIAC motor control. Why is my resistor burning?

I have designed a digital motor controller using the following circuit. One of my resistors keeps overheating. There is a zero-cross detector elsewhere in the circuit used to time the firing of the ...
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2 votes
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relays 5V 10A and 12V 30V stop working after a few days of use

We built a system for heating 3 bioelectrochemical reactors, but after a certain time of operation the system starts to heat up. We identified that when this occurs, the relay works despite the light ...
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RCD clamp and RC snubber design question

I have two questions about the RCD clamp and the RC snubber question in flyback. Below the figure is a CCM flyback converter with primary and secondary clamps and snubbers. Here are my questions: ...
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Snubber in low power Push-Pull DC/DC converter

I'm designing a low-voltage and low-power push-pull converter for an isolated communication interface. The output will be 5 V, 0.5 A. I would like to have an hint about snubber networks on the primary ...
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Sub-miniature signal relay (normally closed SPDT) getting stuck due to arcing

I have a 24V motor which is driven bi-directionally with PWM using DRV8873 H-Bridge motor controller. The circuit looks as follows: For normally driving the motor in either of the direction, I switch ...
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Why a low pass filter across relay contacts instead of a high pass filter?

I have found a snubber, it is a low pass filter. It doesn't make sense to have a low pass filter across the contact. I would consider transients such as arcing to be high frequency; therefore, a high ...
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Switching motor through contactor using 5V mcu signal

Is the following procedure safe/ok? MCU turns on the optocoupler (MOC3063, datasheet) Optocoupler output turns on a triac (BT139-600, rated 16A, 600V AC) Triac supplies 220V AC voltage to the bobbin ...
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Flyback diodes instead of a resistor in series with a capacitor in parallel with the inductor

Why do people use flyback diodes instead of a resistor in series with a capacitor in parallel with the inductor? Wouldn't it be just as good? It would also have the benefit of working with motors that ...
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How to calculate the power dissipation of the snubber RC?

I have this snubber circuit in the DC-DC Converter. Can someone tell me how to calculate the power dissipation of the encircled resistor? And what would be the maximum voltage acorss the capacitor? ...
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230VAC Triac snubber resistor arcing

After a successful first design of my AC triac dimmer, I decided to improve it. I did this by adding a snubber circuit, so I could control inductive loads as well. I also added a EMI filter to reduce ...
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Trying to find this specific manufacturer for a diode

I am trying to find these specific diodes and who made it. Thanks for your time in advance. They could be tvs diodes also
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RC Snubber Circuit on Reversing Motor

I have an RC snubber that is in parallel to a DC motor that runs forward and reverse. Is this snubber going to work differently in the forward direction than is does in the reverse direction? Does the ...
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Effects of double snubber for TRIAC on SSR?

I'm designing a PCB where an MCU has to command a TRIAC to drive a coil, when googling an schematic for an SSR, I came across 2 snubber designs, and while researching them this question: Triac snubber:...
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Full-Bridge Mosfet Vds Waveform Problem

I'm trying to build a full-bridge dc-dc converter, PWM signals are ok but drain-source waveform has some problems. Here is drain-source waveform with a proper pwm signal on gate. Then I decided to ...
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Bidirectional TVS supressor instead of Snubber for Triac

I am planning on building my own smart home socket and I want to mainly control LED lamps. But of course I can't make sure that someone is not plugging in let's say a toaster into the socket. (Yes I ...
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Voltage rating of snubber circuit

I am referring a solid state relay circuit from here. The circuit given is below Well I'm new to this, so dam confused with voltage rating of resistance and capacitance of snubber circuit. what would ...
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2 votes
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Designing an RC Snubber for TRIAC motor control

I am designing a snubber to reduce voltage transients for a TRIAC load phase angle control circuit. The snubber is composed by an RC network in parallel with the load. The load is a 230V 5A electric ...
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What is the purpose of this voltage divider (R16 & R19) in the RC snubber circuit?

What is the voltage divider used for in this circuit?
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Stop a Relay H-Bridge for Brushed DC-Motors to get burned

i am using two Relays to create an H-Bridge. This H-Bridge drives a 24V Motor ~3A in both directions. Now i often got the problem, when i turn on a motor and turn it off again, the relay contacts are ...
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Calculating RC snubber network current?

I'm trying to pick the components to use with this DC/DC Buck-Boost Converter. At page 13, the datasheet says, that for input voltages higher than 4.5 V I need to add an extra 2Ω/1nF RC snubber ...
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Secondary snubber in flyback converter

I am designing a flyback converter. Input = 180-240 Vac Output = 15 V, 0.4 A The secondary output seems to be oscillating when the diode is turns on. Oscillating frequency is around 27 MHz. I am using ...
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SMPS Transformer Primary Winding Ringing

We are working on a 24V 4A flyback SMPS design. But when we analyze the primary winding of SMPS transformer, we are determining very high voltage oscillations(ringing) up to 350V. But our DC bus is ...
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Snubber circuit for TRIAC

I have built TRIAC circuit below which I got off the internet. Without the snubber circuit works good, but with snubber the TRIAC is always on. I'm using 9v ac just for testing purposes. Can someone ...
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Best positioning of snubber capacitors for Full-Bridge transistors

Two options for the location of snubber (film) capacitors. In the first circuit, both capacitors stand up to before the bridge. In the second variant, each capacitor stands next to the half-bridge. I ...
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Secondary voltage spike in flyback transformer

simulate this circuit – Schematic created using CircuitLab I am using a TNY264 IC to make a custom flyback transformer. (U1 is the TNY264.) The primary to secondary turns ratio is 10 with the ...
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1 vote
2 answers
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why don't we see more snubbers in schematics?

Introduction Let me start by saying that I know what a snubber is and how to implement one. I learnt how to use them when developing power electronics. Needed to reduce EMI in switchers, but they are ...
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Snubber on rectifier diode

It is rare to see a snubber circuit added transistor like that. On the secondary side, an NPN transistor is paralleled to a snubber capacitor. How does it work? Is it useful or just little ...
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Circuit for reversing a DC Motor with two 5 pin relays

I'm manufacturing a "running boar" target for my local shooting club. The boar will have an on-board 12V battery and drive a wheel via a wiper motor. Boar starts its run on the end of a ...
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Relay circuit with MOC3021 and BT136

I am designing a relay circuit with MOC3021 and BT136 from this datasheet. I know the importance of snubber circut(39ohm resistance and 0.01uf capacitor). But I have no idea why 360,470 ohm ...
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TRIAC confusion

First for some quick background: You might be aware of my other threads in which I pose a problem with micro-controller to WiFi-command an existing coffee machine which had (as happens with a lot of ...
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3 votes
2 answers
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Strange minimalist power supply, which IC?

I encountered this little gadget, wall-pluggable, and I opened it, I don't even know what is supposed to do! I can vaguely remember it being some kind of "anti-mosquito" thing. I managed to ...
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Reduce switching noise on autotransformer

I am trying to achieve the same thing they are talking about in this post, which is controling an autotransformer via software. I accidently even got the exact same autotransformer, but instead of a ...
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Snubbing LC oscillation

I have a series LC resonant circuit L = 44.4mH C = 36.5pF fr = 125kHz. It is LF RFID antenna. The LC circuit is powered by an H-bridge with MOSFET transistors. 125kHz carrier frequency, 1kHz ...
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2 votes
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554 views

RC Snubber connection

I'm going to use this AC Dimmer Module with an inductive load, so I plan to help it by adding an RC Snubber Module. Most of the schemes show that the best way to use an RC snubber is to connect it ...
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